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root / htmltest / includes / file.inc @ 85ad3d82

1
<?php
2

    
3
/**
4
 * @file
5
 * API for handling file uploads and server file management.
6
 */
7

    
8
/**
9
 * Manually include stream wrapper code.
10
 *
11
 * Stream wrapper code is included here because there are cases where
12
 * File API is needed before a bootstrap, or in an alternate order (e.g.
13
 * maintenance theme).
14
 */
15
require_once DRUPAL_ROOT . '/includes/stream_wrappers.inc';
16

    
17
/**
18
 * @defgroup file File interface
19
 * @{
20
 * Common file handling functions.
21
 *
22
 * Fields on the file object:
23
 * - fid: File ID
24
 * - uid: The {users}.uid of the user who is associated with the file.
25
 * - filename: Name of the file with no path components. This may differ from
26
 *   the basename of the filepath if the file is renamed to avoid overwriting
27
 *   an existing file.
28
 * - uri: URI of the file.
29
 * - filemime: The file's MIME type.
30
 * - filesize: The size of the file in bytes.
31
 * - status: A bitmapped field indicating the status of the file. The first 8
32
 *   bits are reserved for Drupal core. The least significant bit indicates
33
 *   temporary (0) or permanent (1). Temporary files older than
34
 *   DRUPAL_MAXIMUM_TEMP_FILE_AGE will be removed during cron runs.
35
 * - timestamp: UNIX timestamp for the date the file was added to the database.
36
 */
37

    
38
/**
39
 * Flag used by file_prepare_directory() -- create directory if not present.
40
 */
41
define('FILE_CREATE_DIRECTORY', 1);
42

    
43
/**
44
 * Flag used by file_prepare_directory() -- file permissions may be changed.
45
 */
46
define('FILE_MODIFY_PERMISSIONS', 2);
47

    
48
/**
49
 * Flag for dealing with existing files: Appends number until name is unique.
50
 */
51
define('FILE_EXISTS_RENAME', 0);
52

    
53
/**
54
 * Flag for dealing with existing files: Replace the existing file.
55
 */
56
define('FILE_EXISTS_REPLACE', 1);
57

    
58
/**
59
 * Flag for dealing with existing files: Do nothing and return FALSE.
60
 */
61
define('FILE_EXISTS_ERROR', 2);
62

    
63
/**
64
 * Indicates that the file is permanent and should not be deleted.
65
 *
66
 * Temporary files older than DRUPAL_MAXIMUM_TEMP_FILE_AGE will be removed
67
 * during cron runs, but permanent files will not be removed during the file
68
 * garbage collection process.
69
 */
70
define('FILE_STATUS_PERMANENT', 1);
71

    
72
/**
73
 * Provides Drupal stream wrapper registry.
74
 *
75
 * A stream wrapper is an abstraction of a file system that allows Drupal to
76
 * use the same set of methods to access both local files and remote resources.
77
 *
78
 * Provide a facility for managing and querying user-defined stream wrappers
79
 * in PHP. PHP's internal stream_get_wrappers() doesn't return the class
80
 * registered to handle a stream, which we need to be able to find the handler
81
 * for class instantiation.
82
 *
83
 * If a module registers a scheme that is already registered with PHP, the
84
 * existing scheme will be unregistered and replaced with the specified class.
85
 *
86
 * A stream is referenced as "scheme://target".
87
 *
88
 * The optional $filter parameter can be used to retrieve only the stream
89
 * wrappers that are appropriate for particular usage. For example, this returns
90
 * only stream wrappers that use local file storage:
91
 * @code
92
 *   $local_stream_wrappers = file_get_stream_wrappers(STREAM_WRAPPERS_LOCAL);
93
 * @endcode
94
 *
95
 * The $filter parameter can only filter to types containing a particular flag.
96
 * In some cases, you may want to filter to types that do not contain a
97
 * particular flag. For example, you may want to retrieve all stream wrappers
98
 * that are not writable, or all stream wrappers that are not local. PHP's
99
 * array_diff_key() function can be used to help with this. For example, this
100
 * returns only stream wrappers that do not use local file storage:
101
 * @code
102
 *   $remote_stream_wrappers = array_diff_key(file_get_stream_wrappers(STREAM_WRAPPERS_ALL), file_get_stream_wrappers(STREAM_WRAPPERS_LOCAL));
103
 * @endcode
104
 *
105
 * @param $filter
106
 *   (Optional) Filters out all types except those with an on bit for each on
107
 *   bit in $filter. For example, if $filter is STREAM_WRAPPERS_WRITE_VISIBLE,
108
 *   which is equal to (STREAM_WRAPPERS_READ | STREAM_WRAPPERS_WRITE |
109
 *   STREAM_WRAPPERS_VISIBLE), then only stream wrappers with all three of these
110
 *   bits set are returned. Defaults to STREAM_WRAPPERS_ALL, which returns all
111
 *   registered stream wrappers.
112
 *
113
 * @return
114
 *   An array keyed by scheme, with values containing an array of information
115
 *   about the stream wrapper, as returned by hook_stream_wrappers(). If $filter
116
 *   is omitted or set to STREAM_WRAPPERS_ALL, the entire Drupal stream wrapper
117
 *   registry is returned. Otherwise only the stream wrappers whose 'type'
118
 *   bitmask has an on bit for each bit specified in $filter are returned.
119
 *
120
 * @see hook_stream_wrappers()
121
 * @see hook_stream_wrappers_alter()
122
 */
123
function file_get_stream_wrappers($filter = STREAM_WRAPPERS_ALL) {
124
  $wrappers_storage = &drupal_static(__FUNCTION__);
125

    
126
  if (!isset($wrappers_storage)) {
127
    $wrappers = module_invoke_all('stream_wrappers');
128
    foreach ($wrappers as $scheme => $info) {
129
      // Add defaults.
130
      $wrappers[$scheme] += array('type' => STREAM_WRAPPERS_NORMAL);
131
    }
132
    drupal_alter('stream_wrappers', $wrappers);
133
    $existing = stream_get_wrappers();
134
    foreach ($wrappers as $scheme => $info) {
135
      // We only register classes that implement our interface.
136
      if (in_array('DrupalStreamWrapperInterface', class_implements($info['class']), TRUE)) {
137
        // Record whether we are overriding an existing scheme.
138
        if (in_array($scheme, $existing, TRUE)) {
139
          $wrappers[$scheme]['override'] = TRUE;
140
          stream_wrapper_unregister($scheme);
141
        }
142
        else {
143
          $wrappers[$scheme]['override'] = FALSE;
144
        }
145
        if (($info['type'] & STREAM_WRAPPERS_LOCAL) == STREAM_WRAPPERS_LOCAL) {
146
          stream_wrapper_register($scheme, $info['class']);
147
        }
148
        else {
149
          stream_wrapper_register($scheme, $info['class'], STREAM_IS_URL);
150
        }
151
      }
152
      // Pre-populate the static cache with the filters most typically used.
153
      $wrappers_storage[STREAM_WRAPPERS_ALL][$scheme] = $wrappers[$scheme];
154
      if (($info['type'] & STREAM_WRAPPERS_WRITE_VISIBLE) == STREAM_WRAPPERS_WRITE_VISIBLE) {
155
        $wrappers_storage[STREAM_WRAPPERS_WRITE_VISIBLE][$scheme] = $wrappers[$scheme];
156
      }
157
    }
158
  }
159

    
160
  if (!isset($wrappers_storage[$filter])) {
161
    $wrappers_storage[$filter] = array();
162
    foreach ($wrappers_storage[STREAM_WRAPPERS_ALL] as $scheme => $info) {
163
      // Bit-wise filter.
164
      if (($info['type'] & $filter) == $filter) {
165
        $wrappers_storage[$filter][$scheme] = $info;
166
      }
167
    }
168
  }
169

    
170
  return $wrappers_storage[$filter];
171
}
172

    
173
/**
174
 * Returns the stream wrapper class name for a given scheme.
175
 *
176
 * @param $scheme
177
 *   Stream scheme.
178
 *
179
 * @return
180
 *   Return string if a scheme has a registered handler, or FALSE.
181
 */
182
function file_stream_wrapper_get_class($scheme) {
183
  $wrappers = file_get_stream_wrappers();
184
  return empty($wrappers[$scheme]) ? FALSE : $wrappers[$scheme]['class'];
185
}
186

    
187
/**
188
 * Returns the scheme of a URI (e.g. a stream).
189
 *
190
 * @param $uri
191
 *   A stream, referenced as "scheme://target".
192
 *
193
 * @return
194
 *   A string containing the name of the scheme, or FALSE if none. For example,
195
 *   the URI "public://example.txt" would return "public".
196
 *
197
 * @see file_uri_target()
198
 */
199
function file_uri_scheme($uri) {
200
  $position = strpos($uri, '://');
201
  return $position ? substr($uri, 0, $position) : FALSE;
202
}
203

    
204
/**
205
 * Checks that the scheme of a stream URI is valid.
206
 *
207
 * Confirms that there is a registered stream handler for the provided scheme
208
 * and that it is callable. This is useful if you want to confirm a valid
209
 * scheme without creating a new instance of the registered handler.
210
 *
211
 * @param $scheme
212
 *   A URI scheme, a stream is referenced as "scheme://target".
213
 *
214
 * @return
215
 *   Returns TRUE if the string is the name of a validated stream,
216
 *   or FALSE if the scheme does not have a registered handler.
217
 */
218
function file_stream_wrapper_valid_scheme($scheme) {
219
  // Does the scheme have a registered handler that is callable?
220
  $class = file_stream_wrapper_get_class($scheme);
221
  if (class_exists($class)) {
222
    return TRUE;
223
  }
224
  else {
225
    return FALSE;
226
  }
227
}
228

    
229

    
230
/**
231
 * Returns the part of a URI after the schema.
232
 *
233
 * @param $uri
234
 *   A stream, referenced as "scheme://target".
235
 *
236
 * @return
237
 *   A string containing the target (path), or FALSE if none.
238
 *   For example, the URI "public://sample/test.txt" would return
239
 *   "sample/test.txt".
240
 *
241
 * @see file_uri_scheme()
242
 */
243
function file_uri_target($uri) {
244
  $data = explode('://', $uri, 2);
245

    
246
  // Remove erroneous leading or trailing, forward-slashes and backslashes.
247
  return count($data) == 2 ? trim($data[1], '\/') : FALSE;
248
}
249

    
250
/**
251
 * Gets the default file stream implementation.
252
 *
253
 * @return
254
 *   'public', 'private' or any other file scheme defined as the default.
255
 */
256
function file_default_scheme() {
257
  return variable_get('file_default_scheme', 'public');
258
}
259

    
260
/**
261
 * Normalizes a URI by making it syntactically correct.
262
 *
263
 * A stream is referenced as "scheme://target".
264
 *
265
 * The following actions are taken:
266
 * - Remove trailing slashes from target
267
 * - Trim erroneous leading slashes from target. e.g. ":///" becomes "://".
268
 *
269
 * @param $uri
270
 *   String reference containing the URI to normalize.
271
 *
272
 * @return
273
 *   The normalized URI.
274
 */
275
function file_stream_wrapper_uri_normalize($uri) {
276
  $scheme = file_uri_scheme($uri);
277

    
278
  if ($scheme && file_stream_wrapper_valid_scheme($scheme)) {
279
    $target = file_uri_target($uri);
280

    
281
    if ($target !== FALSE) {
282
      $uri = $scheme . '://' . $target;
283
    }
284
  }
285
  return $uri;
286
}
287

    
288
/**
289
 * Returns a reference to the stream wrapper class responsible for a given URI.
290
 *
291
 * The scheme determines the stream wrapper class that should be
292
 * used by consulting the stream wrapper registry.
293
 *
294
 * @param $uri
295
 *   A stream, referenced as "scheme://target".
296
 *
297
 * @return
298
 *   Returns a new stream wrapper object appropriate for the given URI or FALSE
299
 *   if no registered handler could be found. For example, a URI of
300
 *   "private://example.txt" would return a new private stream wrapper object
301
 *   (DrupalPrivateStreamWrapper).
302
 */
303
function file_stream_wrapper_get_instance_by_uri($uri) {
304
  $scheme = file_uri_scheme($uri);
305
  $class = file_stream_wrapper_get_class($scheme);
306
  if (class_exists($class)) {
307
    $instance = new $class();
308
    $instance->setUri($uri);
309
    return $instance;
310
  }
311
  else {
312
    return FALSE;
313
  }
314
}
315

    
316
/**
317
 * Returns a reference to the stream wrapper class responsible for a scheme.
318
 *
319
 * This helper method returns a stream instance using a scheme. That is, the
320
 * passed string does not contain a "://". For example, "public" is a scheme
321
 * but "public://" is a URI (stream). This is because the later contains both
322
 * a scheme and target despite target being empty.
323
 *
324
 * Note: the instance URI will be initialized to "scheme://" so that you can
325
 * make the customary method calls as if you had retrieved an instance by URI.
326
 *
327
 * @param $scheme
328
 *   If the stream was "public://target", "public" would be the scheme.
329
 *
330
 * @return
331
 *   Returns a new stream wrapper object appropriate for the given $scheme.
332
 *   For example, for the public scheme a stream wrapper object
333
 *   (DrupalPublicStreamWrapper).
334
 *   FALSE is returned if no registered handler could be found.
335
 */
336
function file_stream_wrapper_get_instance_by_scheme($scheme) {
337
  $class = file_stream_wrapper_get_class($scheme);
338
  if (class_exists($class)) {
339
    $instance = new $class();
340
    $instance->setUri($scheme . '://');
341
    return $instance;
342
  }
343
  else {
344
    return FALSE;
345
  }
346
}
347

    
348
/**
349
 * Creates a web-accessible URL for a stream to an external or local file.
350
 *
351
 * Compatibility: normal paths and stream wrappers.
352
 *
353
 * There are two kinds of local files:
354
 * - "managed files", i.e. those stored by a Drupal-compatible stream wrapper.
355
 *   These are files that have either been uploaded by users or were generated
356
 *   automatically (for example through CSS aggregation).
357
 * - "shipped files", i.e. those outside of the files directory, which ship as
358
 *   part of Drupal core or contributed modules or themes.
359
 *
360
 * @param $uri
361
 *   The URI to a file for which we need an external URL, or the path to a
362
 *   shipped file.
363
 *
364
 * @return
365
 *   A string containing a URL that may be used to access the file.
366
 *   If the provided string already contains a preceding 'http', 'https', or
367
 *   '/', nothing is done and the same string is returned. If a stream wrapper
368
 *   could not be found to generate an external URL, then FALSE is returned.
369
 *
370
 * @see http://drupal.org/node/515192
371
 */
372
function file_create_url($uri) {
373
  // Allow the URI to be altered, e.g. to serve a file from a CDN or static
374
  // file server.
375
  drupal_alter('file_url', $uri);
376

    
377
  $scheme = file_uri_scheme($uri);
378

    
379
  if (!$scheme) {
380
    // Allow for:
381
    // - root-relative URIs (e.g. /foo.jpg in http://example.com/foo.jpg)
382
    // - protocol-relative URIs (e.g. //bar.jpg, which is expanded to
383
    //   http://example.com/bar.jpg by the browser when viewing a page over
384
    //   HTTP and to https://example.com/bar.jpg when viewing a HTTPS page)
385
    // Both types of relative URIs are characterized by a leading slash, hence
386
    // we can use a single check.
387
    if (drupal_substr($uri, 0, 1) == '/') {
388
      return $uri;
389
    }
390
    else {
391
      // If this is not a properly formatted stream, then it is a shipped file.
392
      // Therefore, return the urlencoded URI with the base URL prepended.
393
      return $GLOBALS['base_url'] . '/' . drupal_encode_path($uri);
394
    }
395
  }
396
  elseif ($scheme == 'http' || $scheme == 'https') {
397
    // Check for HTTP so that we don't have to implement getExternalUrl() for
398
    // the HTTP wrapper.
399
    return $uri;
400
  }
401
  else {
402
    // Attempt to return an external URL using the appropriate wrapper.
403
    if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
404
      return $wrapper->getExternalUrl();
405
    }
406
    else {
407
      return FALSE;
408
    }
409
  }
410
}
411

    
412
/**
413
 * Checks that the directory exists and is writable.
414
 *
415
 * Directories need to have execute permissions to be considered a directory by
416
 * FTP servers, etc.
417
 *
418
 * @param $directory
419
 *   A string reference containing the name of a directory path or URI. A
420
 *   trailing slash will be trimmed from a path.
421
 * @param $options
422
 *   A bitmask to indicate if the directory should be created if it does
423
 *   not exist (FILE_CREATE_DIRECTORY) or made writable if it is read-only
424
 *   (FILE_MODIFY_PERMISSIONS).
425
 *
426
 * @return
427
 *   TRUE if the directory exists (or was created) and is writable. FALSE
428
 *   otherwise.
429
 */
430
function file_prepare_directory(&$directory, $options = FILE_MODIFY_PERMISSIONS) {
431
  if (!file_stream_wrapper_valid_scheme(file_uri_scheme($directory))) {
432
    // Only trim if we're not dealing with a stream.
433
    $directory = rtrim($directory, '/\\');
434
  }
435

    
436
  // Check if directory exists.
437
  if (!is_dir($directory)) {
438
    // Let mkdir() recursively create directories and use the default directory
439
    // permissions.
440
    if (($options & FILE_CREATE_DIRECTORY) && @drupal_mkdir($directory, NULL, TRUE)) {
441
      return drupal_chmod($directory);
442
    }
443
    return FALSE;
444
  }
445
  // The directory exists, so check to see if it is writable.
446
  $writable = is_writable($directory);
447
  if (!$writable && ($options & FILE_MODIFY_PERMISSIONS)) {
448
    return drupal_chmod($directory);
449
  }
450

    
451
  return $writable;
452
}
453

    
454
/**
455
 * Creates a .htaccess file in each Drupal files directory if it is missing.
456
 */
457
function file_ensure_htaccess() {
458
  file_create_htaccess('public://', FALSE);
459
  if (variable_get('file_private_path', FALSE)) {
460
    file_create_htaccess('private://', TRUE);
461
  }
462
  file_create_htaccess('temporary://', TRUE);
463
}
464

    
465
/**
466
 * Creates a .htaccess file in the given directory.
467
 *
468
 * @param $directory
469
 *   The directory.
470
 * @param $private
471
 *   FALSE indicates that $directory should be an open and public directory.
472
 *   The default is TRUE which indicates a private and protected directory.
473
 * @param $force_overwrite
474
 *   Set to TRUE to attempt to overwrite the existing .htaccess file if one is
475
 *   already present. Defaults to FALSE.
476
 */
477
function file_create_htaccess($directory, $private = TRUE, $force_overwrite = FALSE) {
478
  if (file_uri_scheme($directory)) {
479
    $directory = file_stream_wrapper_uri_normalize($directory);
480
  }
481
  else {
482
    $directory = rtrim($directory, '/\\');
483
  }
484
  $htaccess_path =  $directory . '/.htaccess';
485

    
486
  if (file_exists($htaccess_path) && !$force_overwrite) {
487
    // Short circuit if the .htaccess file already exists.
488
    return;
489
  }
490

    
491
  $htaccess_lines = file_htaccess_lines($private);
492

    
493
  // Write the .htaccess file.
494
  if (file_put_contents($htaccess_path, $htaccess_lines)) {
495
    drupal_chmod($htaccess_path, 0444);
496
  }
497
  else {
498
    $variables = array('%directory' => $directory, '!htaccess' => '<br />' . nl2br(check_plain($htaccess_lines)));
499
    watchdog('security', "Security warning: Couldn't write .htaccess file. Please create a .htaccess file in your %directory directory which contains the following lines: <code>!htaccess</code>", $variables, WATCHDOG_ERROR);
500
  }
501
}
502

    
503
/**
504
 * Returns the standard .htaccess lines that Drupal writes to file directories.
505
 *
506
 * @param $private
507
 *   (Optional) Set to FALSE to return the .htaccess lines for an open and
508
 *   public directory. The default is TRUE, which returns the .htaccess lines
509
 *   for a private and protected directory.
510
 *
511
 * @return
512
 *   A string representing the desired contents of the .htaccess file.
513
 *
514
 * @see file_create_htaccess()
515
 */
516
function file_htaccess_lines($private = TRUE) {
517
  $lines = <<<EOF
518
# Turn off all options we don't need.
519
Options None
520
Options +FollowSymLinks
521

    
522
# Set the catch-all handler to prevent scripts from being executed.
523
SetHandler Drupal_Security_Do_Not_Remove_See_SA_2006_006
524
<Files *>
525
  # Override the handler again if we're run later in the evaluation list.
526
  SetHandler Drupal_Security_Do_Not_Remove_See_SA_2013_003
527
</Files>
528

    
529
# If we know how to do it safely, disable the PHP engine entirely.
530
<IfModule mod_php5.c>
531
  php_flag engine off
532
</IfModule>
533
EOF;
534

    
535
  if ($private) {
536
    $lines = "Deny from all\n\n" . $lines;
537
  }
538

    
539
  return $lines;
540
}
541

    
542
/**
543
 * Loads file objects from the database.
544
 *
545
 * @param $fids
546
 *   An array of file IDs.
547
 * @param $conditions
548
 *   (deprecated) An associative array of conditions on the {file_managed}
549
 *   table, where the keys are the database fields and the values are the
550
 *   values those fields must have. Instead, it is preferable to use
551
 *   EntityFieldQuery to retrieve a list of entity IDs loadable by
552
 *   this function.
553
 *
554
 * @return
555
 *   An array of file objects, indexed by fid.
556
 *
557
 * @todo Remove $conditions in Drupal 8.
558
 *
559
 * @see hook_file_load()
560
 * @see file_load()
561
 * @see entity_load()
562
 * @see EntityFieldQuery
563
 */
564
function file_load_multiple($fids = array(), $conditions = array()) {
565
  return entity_load('file', $fids, $conditions);
566
}
567

    
568
/**
569
 * Loads a single file object from the database.
570
 *
571
 * @param $fid
572
 *   A file ID.
573
 *
574
 * @return
575
 *   An object representing the file, or FALSE if the file was not found.
576
 *
577
 * @see hook_file_load()
578
 * @see file_load_multiple()
579
 */
580
function file_load($fid) {
581
  $files = file_load_multiple(array($fid), array());
582
  return reset($files);
583
}
584

    
585
/**
586
 * Saves a file object to the database.
587
 *
588
 * If the $file->fid is not set a new record will be added.
589
 *
590
 * @param $file
591
 *   A file object returned by file_load().
592
 *
593
 * @return
594
 *   The updated file object.
595
 *
596
 * @see hook_file_insert()
597
 * @see hook_file_update()
598
 */
599
function file_save(stdClass $file) {
600
  $file->timestamp = REQUEST_TIME;
601
  $file->filesize = filesize($file->uri);
602

    
603
  // Load the stored entity, if any.
604
  if (!empty($file->fid) && !isset($file->original)) {
605
    $file->original = entity_load_unchanged('file', $file->fid);
606
  }
607

    
608
  module_invoke_all('file_presave', $file);
609
  module_invoke_all('entity_presave', $file, 'file');
610

    
611
  if (empty($file->fid)) {
612
    drupal_write_record('file_managed', $file);
613
    // Inform modules about the newly added file.
614
    module_invoke_all('file_insert', $file);
615
    module_invoke_all('entity_insert', $file, 'file');
616
  }
617
  else {
618
    drupal_write_record('file_managed', $file, 'fid');
619
    // Inform modules that the file has been updated.
620
    module_invoke_all('file_update', $file);
621
    module_invoke_all('entity_update', $file, 'file');
622
  }
623

    
624
  unset($file->original);
625
  return $file;
626
}
627

    
628
/**
629
 * Determines where a file is used.
630
 *
631
 * @param $file
632
 *   A file object.
633
 *
634
 * @return
635
 *   A nested array with usage data. The first level is keyed by module name,
636
 *   the second by object type and the third by the object id. The value
637
 *   of the third level contains the usage count.
638
 *
639
 * @see file_usage_add()
640
 * @see file_usage_delete()
641
 */
642
function file_usage_list(stdClass $file) {
643
  $result = db_select('file_usage', 'f')
644
    ->fields('f', array('module', 'type', 'id', 'count'))
645
    ->condition('fid', $file->fid)
646
    ->condition('count', 0, '>')
647
    ->execute();
648
  $references = array();
649
  foreach ($result as $usage) {
650
    $references[$usage->module][$usage->type][$usage->id] = $usage->count;
651
  }
652
  return $references;
653
}
654

    
655
/**
656
 * Records that a module is using a file.
657
 *
658
 * This usage information will be queried during file_delete() to ensure that
659
 * a file is not in use before it is physically removed from disk.
660
 *
661
 * Examples:
662
 * - A module that associates files with nodes, so $type would be
663
 *   'node' and $id would be the node's nid. Files for all revisions are stored
664
 *   within a single nid.
665
 * - The User module associates an image with a user, so $type would be 'user'
666
 *   and the $id would be the user's uid.
667
 *
668
 * @param $file
669
 *   A file object.
670
 * @param $module
671
 *   The name of the module using the file.
672
 * @param $type
673
 *   The type of the object that contains the referenced file.
674
 * @param $id
675
 *   The unique, numeric ID of the object containing the referenced file.
676
 * @param $count
677
 *   (optional) The number of references to add to the object. Defaults to 1.
678
 *
679
 * @see file_usage_list()
680
 * @see file_usage_delete()
681
 */
682
function file_usage_add(stdClass $file, $module, $type, $id, $count = 1) {
683
  db_merge('file_usage')
684
    ->key(array(
685
      'fid' => $file->fid,
686
      'module' => $module,
687
      'type' => $type,
688
      'id' => $id,
689
    ))
690
    ->fields(array('count' => $count))
691
    ->expression('count', 'count + :count', array(':count' => $count))
692
    ->execute();
693
}
694

    
695
/**
696
 * Removes a record to indicate that a module is no longer using a file.
697
 *
698
 * The file_delete() function is typically called after removing a file usage
699
 * to remove the record from the file_managed table and delete the file itself.
700
 *
701
 * @param $file
702
 *   A file object.
703
 * @param $module
704
 *   The name of the module using the file.
705
 * @param $type
706
 *   (optional) The type of the object that contains the referenced file. May
707
 *   be omitted if all module references to a file are being deleted.
708
 * @param $id
709
 *   (optional) The unique, numeric ID of the object containing the referenced
710
 *   file. May be omitted if all module references to a file are being deleted.
711
 * @param $count
712
 *   (optional) The number of references to delete from the object. Defaults to
713
 *   1. 0 may be specified to delete all references to the file within a
714
 *   specific object.
715
 *
716
 * @see file_usage_add()
717
 * @see file_usage_list()
718
 * @see file_delete()
719
 */
720
function file_usage_delete(stdClass $file, $module, $type = NULL, $id = NULL, $count = 1) {
721
  // Delete rows that have a exact or less value to prevent empty rows.
722
  $query = db_delete('file_usage')
723
    ->condition('module', $module)
724
    ->condition('fid', $file->fid);
725
  if ($type && $id) {
726
    $query
727
      ->condition('type', $type)
728
      ->condition('id', $id);
729
  }
730
  if ($count) {
731
    $query->condition('count', $count, '<=');
732
  }
733
  $result = $query->execute();
734

    
735
  // If the row has more than the specified count decrement it by that number.
736
  if (!$result && $count > 0) {
737
    $query = db_update('file_usage')
738
      ->condition('module', $module)
739
      ->condition('fid', $file->fid);
740
    if ($type && $id) {
741
      $query
742
        ->condition('type', $type)
743
        ->condition('id', $id);
744
    }
745
    $query->expression('count', 'count - :count', array(':count' => $count));
746
    $query->execute();
747
  }
748
}
749

    
750
/**
751
 * Copies a file to a new location and adds a file record to the database.
752
 *
753
 * This function should be used when manipulating files that have records
754
 * stored in the database. This is a powerful function that in many ways
755
 * performs like an advanced version of copy().
756
 * - Checks if $source and $destination are valid and readable/writable.
757
 * - If file already exists in $destination either the call will error out,
758
 *   replace the file or rename the file based on the $replace parameter.
759
 * - If the $source and $destination are equal, the behavior depends on the
760
 *   $replace parameter. FILE_EXISTS_REPLACE will error out. FILE_EXISTS_RENAME
761
 *   will rename the file until the $destination is unique.
762
 * - Adds the new file to the files database. If the source file is a
763
 *   temporary file, the resulting file will also be a temporary file. See
764
 *   file_save_upload() for details on temporary files.
765
 *
766
 * @param $source
767
 *   A file object.
768
 * @param $destination
769
 *   A string containing the destination that $source should be copied to.
770
 *   This must be a stream wrapper URI.
771
 * @param $replace
772
 *   Replace behavior when the destination file already exists:
773
 *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
774
 *       the destination name exists then its database entry will be updated. If
775
 *       no database entry is found then a new one will be created.
776
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
777
 *       unique.
778
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
779
 *
780
 * @return
781
 *   File object if the copy is successful, or FALSE in the event of an error.
782
 *
783
 * @see file_unmanaged_copy()
784
 * @see hook_file_copy()
785
 */
786
function file_copy(stdClass $source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
787
  if (!file_valid_uri($destination)) {
788
    if (($realpath = drupal_realpath($source->uri)) !== FALSE) {
789
      watchdog('file', 'File %file (%realpath) could not be copied, because the destination %destination is invalid. This is often caused by improper use of file_copy() or a missing stream wrapper.', array('%file' => $source->uri, '%realpath' => $realpath, '%destination' => $destination));
790
    }
791
    else {
792
      watchdog('file', 'File %file could not be copied, because the destination %destination is invalid. This is often caused by improper use of file_copy() or a missing stream wrapper.', array('%file' => $source->uri, '%destination' => $destination));
793
    }
794
    drupal_set_message(t('The specified file %file could not be copied, because the destination is invalid. More information is available in the system log.', array('%file' => $source->uri)), 'error');
795
    return FALSE;
796
  }
797

    
798
  if ($uri = file_unmanaged_copy($source->uri, $destination, $replace)) {
799
    $file = clone $source;
800
    $file->fid = NULL;
801
    $file->uri = $uri;
802
    $file->filename = drupal_basename($uri);
803
    // If we are replacing an existing file re-use its database record.
804
    if ($replace == FILE_EXISTS_REPLACE) {
805
      $existing_files = file_load_multiple(array(), array('uri' => $uri));
806
      if (count($existing_files)) {
807
        $existing = reset($existing_files);
808
        $file->fid = $existing->fid;
809
        $file->filename = $existing->filename;
810
      }
811
    }
812
    // If we are renaming around an existing file (rather than a directory),
813
    // use its basename for the filename.
814
    elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
815
      $file->filename = drupal_basename($destination);
816
    }
817

    
818
    $file = file_save($file);
819

    
820
    // Inform modules that the file has been copied.
821
    module_invoke_all('file_copy', $file, $source);
822

    
823
    return $file;
824
  }
825
  return FALSE;
826
}
827

    
828
/**
829
 * Determines whether the URI has a valid scheme for file API operations.
830
 *
831
 * There must be a scheme and it must be a Drupal-provided scheme like
832
 * 'public', 'private', 'temporary', or an extension provided with
833
 * hook_stream_wrappers().
834
 *
835
 * @param $uri
836
 *   The URI to be tested.
837
 *
838
 * @return
839
 *   TRUE if the URI is allowed.
840
 */
841
function file_valid_uri($uri) {
842
  // Assert that the URI has an allowed scheme. Barepaths are not allowed.
843
  $uri_scheme = file_uri_scheme($uri);
844
  if (empty($uri_scheme) || !file_stream_wrapper_valid_scheme($uri_scheme)) {
845
    return FALSE;
846
  }
847
  return TRUE;
848
}
849

    
850
/**
851
 * Copies a file to a new location without invoking the file API.
852
 *
853
 * This is a powerful function that in many ways performs like an advanced
854
 * version of copy().
855
 * - Checks if $source and $destination are valid and readable/writable.
856
 * - If file already exists in $destination either the call will error out,
857
 *   replace the file or rename the file based on the $replace parameter.
858
 * - If the $source and $destination are equal, the behavior depends on the
859
 *   $replace parameter. FILE_EXISTS_REPLACE will error out. FILE_EXISTS_RENAME
860
 *   will rename the file until the $destination is unique.
861
 * - Provides a fallback using realpaths if the move fails using stream
862
 *   wrappers. This can occur because PHP's copy() function does not properly
863
 *   support streams if safe_mode or open_basedir are enabled. See
864
 *   https://bugs.php.net/bug.php?id=60456
865
 *
866
 * @param $source
867
 *   A string specifying the filepath or URI of the source file.
868
 * @param $destination
869
 *   A URI containing the destination that $source should be copied to. The
870
 *   URI may be a bare filepath (without a scheme). If this value is omitted,
871
 *   Drupal's default files scheme will be used, usually "public://".
872
 * @param $replace
873
 *   Replace behavior when the destination file already exists:
874
 *   - FILE_EXISTS_REPLACE - Replace the existing file.
875
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
876
 *       unique.
877
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
878
 *
879
 * @return
880
 *   The path to the new file, or FALSE in the event of an error.
881
 *
882
 * @see file_copy()
883
 */
884
function file_unmanaged_copy($source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
885
  $original_source = $source;
886
  $original_destination = $destination;
887

    
888
  // Assert that the source file actually exists.
889
  if (!file_exists($source)) {
890
    // @todo Replace drupal_set_message() calls with exceptions instead.
891
    drupal_set_message(t('The specified file %file could not be copied, because no file by that name exists. Please check that you supplied the correct filename.', array('%file' => $original_source)), 'error');
892
    if (($realpath = drupal_realpath($original_source)) !== FALSE) {
893
      watchdog('file', 'File %file (%realpath) could not be copied because it does not exist.', array('%file' => $original_source, '%realpath' => $realpath));
894
    }
895
    else {
896
      watchdog('file', 'File %file could not be copied because it does not exist.', array('%file' => $original_source));
897
    }
898
    return FALSE;
899
  }
900

    
901
  // Build a destination URI if necessary.
902
  if (!isset($destination)) {
903
    $destination = file_build_uri(drupal_basename($source));
904
  }
905

    
906

    
907
  // Prepare the destination directory.
908
  if (file_prepare_directory($destination)) {
909
    // The destination is already a directory, so append the source basename.
910
    $destination = file_stream_wrapper_uri_normalize($destination . '/' . drupal_basename($source));
911
  }
912
  else {
913
    // Perhaps $destination is a dir/file?
914
    $dirname = drupal_dirname($destination);
915
    if (!file_prepare_directory($dirname)) {
916
      // The destination is not valid.
917
      watchdog('file', 'File %file could not be copied, because the destination directory %destination is not configured correctly.', array('%file' => $original_source, '%destination' => $dirname));
918
      drupal_set_message(t('The specified file %file could not be copied, because the destination directory is not properly configured. This may be caused by a problem with file or directory permissions. More information is available in the system log.', array('%file' => $original_source)), 'error');
919
      return FALSE;
920
    }
921
  }
922

    
923
  // Determine whether we can perform this operation based on overwrite rules.
924
  $destination = file_destination($destination, $replace);
925
  if ($destination === FALSE) {
926
    drupal_set_message(t('The file %file could not be copied because a file by that name already exists in the destination directory.', array('%file' => $original_source)), 'error');
927
    watchdog('file', 'File %file could not be copied because a file by that name already exists in the destination directory (%directory)', array('%file' => $original_source, '%directory' => $destination));
928
    return FALSE;
929
  }
930

    
931
  // Assert that the source and destination filenames are not the same.
932
  $real_source = drupal_realpath($source);
933
  $real_destination = drupal_realpath($destination);
934
  if ($source == $destination || ($real_source !== FALSE) && ($real_source == $real_destination)) {
935
    drupal_set_message(t('The specified file %file was not copied because it would overwrite itself.', array('%file' => $source)), 'error');
936
    watchdog('file', 'File %file could not be copied because it would overwrite itself.', array('%file' => $source));
937
    return FALSE;
938
  }
939
  // Make sure the .htaccess files are present.
940
  file_ensure_htaccess();
941
  // Perform the copy operation.
942
  if (!@copy($source, $destination)) {
943
    // If the copy failed and realpaths exist, retry the operation using them
944
    // instead.
945
    if ($real_source === FALSE || $real_destination === FALSE || !@copy($real_source, $real_destination)) {
946
      watchdog('file', 'The specified file %file could not be copied to %destination.', array('%file' => $source, '%destination' => $destination), WATCHDOG_ERROR);
947
      return FALSE;
948
    }
949
  }
950

    
951
  // Set the permissions on the new file.
952
  drupal_chmod($destination);
953

    
954
  return $destination;
955
}
956

    
957
/**
958
 * Constructs a URI to Drupal's default files location given a relative path.
959
 */
960
function file_build_uri($path) {
961
  $uri = file_default_scheme() . '://' . $path;
962
  return file_stream_wrapper_uri_normalize($uri);
963
}
964

    
965
/**
966
 * Determines the destination path for a file.
967
 *
968
 * @param $destination
969
 *   A string specifying the desired final URI or filepath.
970
 * @param $replace
971
 *   Replace behavior when the destination file already exists.
972
 *   - FILE_EXISTS_REPLACE - Replace the existing file.
973
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
974
 *       unique.
975
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
976
 *
977
 * @return
978
 *   The destination filepath, or FALSE if the file already exists
979
 *   and FILE_EXISTS_ERROR is specified.
980
 */
981
function file_destination($destination, $replace) {
982
  if (file_exists($destination)) {
983
    switch ($replace) {
984
      case FILE_EXISTS_REPLACE:
985
        // Do nothing here, we want to overwrite the existing file.
986
        break;
987

    
988
      case FILE_EXISTS_RENAME:
989
        $basename = drupal_basename($destination);
990
        $directory = drupal_dirname($destination);
991
        $destination = file_create_filename($basename, $directory);
992
        break;
993

    
994
      case FILE_EXISTS_ERROR:
995
        // Error reporting handled by calling function.
996
        return FALSE;
997
    }
998
  }
999
  return $destination;
1000
}
1001

    
1002
/**
1003
 * Moves a file to a new location and update the file's database entry.
1004
 *
1005
 * Moving a file is performed by copying the file to the new location and then
1006
 * deleting the original.
1007
 * - Checks if $source and $destination are valid and readable/writable.
1008
 * - Performs a file move if $source is not equal to $destination.
1009
 * - If file already exists in $destination either the call will error out,
1010
 *   replace the file or rename the file based on the $replace parameter.
1011
 * - Adds the new file to the files database.
1012
 *
1013
 * @param $source
1014
 *   A file object.
1015
 * @param $destination
1016
 *   A string containing the destination that $source should be moved to.
1017
 *   This must be a stream wrapper URI.
1018
 * @param $replace
1019
 *   Replace behavior when the destination file already exists:
1020
 *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
1021
 *       the destination name exists then its database entry will be updated and
1022
 *       file_delete() called on the source file after hook_file_move is called.
1023
 *       If no database entry is found then the source files record will be
1024
 *       updated.
1025
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
1026
 *       unique.
1027
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
1028
 *
1029
 * @return
1030
 *   Resulting file object for success, or FALSE in the event of an error.
1031
 *
1032
 * @see file_unmanaged_move()
1033
 * @see hook_file_move()
1034
 */
1035
function file_move(stdClass $source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
1036
  if (!file_valid_uri($destination)) {
1037
    if (($realpath = drupal_realpath($source->uri)) !== FALSE) {
1038
      watchdog('file', 'File %file (%realpath) could not be moved, because the destination %destination is invalid. This may be caused by improper use of file_move() or a missing stream wrapper.', array('%file' => $source->uri, '%realpath' => $realpath, '%destination' => $destination));
1039
    }
1040
    else {
1041
      watchdog('file', 'File %file could not be moved, because the destination %destination is invalid. This may be caused by improper use of file_move() or a missing stream wrapper.', array('%file' => $source->uri, '%destination' => $destination));
1042
    }
1043
    drupal_set_message(t('The specified file %file could not be moved, because the destination is invalid. More information is available in the system log.', array('%file' => $source->uri)), 'error');
1044
    return FALSE;
1045
  }
1046

    
1047
  if ($uri = file_unmanaged_move($source->uri, $destination, $replace)) {
1048
    $delete_source = FALSE;
1049

    
1050
    $file = clone $source;
1051
    $file->uri = $uri;
1052
    // If we are replacing an existing file re-use its database record.
1053
    if ($replace == FILE_EXISTS_REPLACE) {
1054
      $existing_files = file_load_multiple(array(), array('uri' => $uri));
1055
      if (count($existing_files)) {
1056
        $existing = reset($existing_files);
1057
        $delete_source = TRUE;
1058
        $file->fid = $existing->fid;
1059
      }
1060
    }
1061
    // If we are renaming around an existing file (rather than a directory),
1062
    // use its basename for the filename.
1063
    elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
1064
      $file->filename = drupal_basename($destination);
1065
    }
1066

    
1067
    $file = file_save($file);
1068

    
1069
    // Inform modules that the file has been moved.
1070
    module_invoke_all('file_move', $file, $source);
1071

    
1072
    if ($delete_source) {
1073
      // Try a soft delete to remove original if it's not in use elsewhere.
1074
      file_delete($source);
1075
    }
1076

    
1077
    return $file;
1078
  }
1079
  return FALSE;
1080
}
1081

    
1082
/**
1083
 * Moves a file to a new location without database changes or hook invocation.
1084
 *
1085
 * @param $source
1086
 *   A string specifying the filepath or URI of the original file.
1087
 * @param $destination
1088
 *   A string containing the destination that $source should be moved to.
1089
 *   This must be a stream wrapper URI. If this value is omitted, Drupal's
1090
 *   default files scheme will be used, usually "public://".
1091
 * @param $replace
1092
 *   Replace behavior when the destination file already exists:
1093
 *   - FILE_EXISTS_REPLACE - Replace the existing file.
1094
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
1095
 *       unique.
1096
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
1097
 *
1098
 * @return
1099
 *   The URI of the moved file, or FALSE in the event of an error.
1100
 *
1101
 * @see file_move()
1102
 */
1103
function file_unmanaged_move($source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
1104
  $filepath = file_unmanaged_copy($source, $destination, $replace);
1105
  if ($filepath == FALSE || file_unmanaged_delete($source) == FALSE) {
1106
    return FALSE;
1107
  }
1108
  return $filepath;
1109
}
1110

    
1111
/**
1112
 * Modifies a filename as needed for security purposes.
1113
 *
1114
 * Munging a file name prevents unknown file extensions from masking exploit
1115
 * files. When web servers such as Apache decide how to process a URL request,
1116
 * they use the file extension. If the extension is not recognized, Apache
1117
 * skips that extension and uses the previous file extension. For example, if
1118
 * the file being requested is exploit.php.pps, and Apache does not recognize
1119
 * the '.pps' extension, it treats the file as PHP and executes it. To make
1120
 * this file name safe for Apache and prevent it from executing as PHP, the
1121
 * .php extension is "munged" into .php_, making the safe file name
1122
 * exploit.php_.pps.
1123
 *
1124
 * Specifically, this function adds an underscore to all extensions that are
1125
 * between 2 and 5 characters in length, internal to the file name, and not
1126
 * included in $extensions.
1127
 *
1128
 * Function behavior is also controlled by the Drupal variable
1129
 * 'allow_insecure_uploads'. If 'allow_insecure_uploads' evaluates to TRUE, no
1130
 * alterations will be made, if it evaluates to FALSE, the filename is 'munged'.
1131
 *
1132
 * @param $filename
1133
 *   File name to modify.
1134
 * @param $extensions
1135
 *   A space-separated list of extensions that should not be altered.
1136
 * @param $alerts
1137
 *   If TRUE, drupal_set_message() will be called to display a message if the
1138
 *   file name was changed.
1139
 *
1140
 * @return
1141
 *   The potentially modified $filename.
1142
 */
1143
function file_munge_filename($filename, $extensions, $alerts = TRUE) {
1144
  $original = $filename;
1145

    
1146
  // Allow potentially insecure uploads for very savvy users and admin
1147
  if (!variable_get('allow_insecure_uploads', 0)) {
1148
    // Remove any null bytes. See http://php.net/manual/security.filesystem.nullbytes.php
1149
    $filename = str_replace(chr(0), '', $filename);
1150

    
1151
    $whitelist = array_unique(explode(' ', trim($extensions)));
1152

    
1153
    // Split the filename up by periods. The first part becomes the basename
1154
    // the last part the final extension.
1155
    $filename_parts = explode('.', $filename);
1156
    $new_filename = array_shift($filename_parts); // Remove file basename.
1157
    $final_extension = array_pop($filename_parts); // Remove final extension.
1158

    
1159
    // Loop through the middle parts of the name and add an underscore to the
1160
    // end of each section that could be a file extension but isn't in the list
1161
    // of allowed extensions.
1162
    foreach ($filename_parts as $filename_part) {
1163
      $new_filename .= '.' . $filename_part;
1164
      if (!in_array($filename_part, $whitelist) && preg_match("/^[a-zA-Z]{2,5}\d?$/", $filename_part)) {
1165
        $new_filename .= '_';
1166
      }
1167
    }
1168
    $filename = $new_filename . '.' . $final_extension;
1169

    
1170
    if ($alerts && $original != $filename) {
1171
      drupal_set_message(t('For security reasons, your upload has been renamed to %filename.', array('%filename' => $filename)));
1172
    }
1173
  }
1174

    
1175
  return $filename;
1176
}
1177

    
1178
/**
1179
 * Undoes the effect of file_munge_filename().
1180
 *
1181
 * @param $filename
1182
 *   String with the filename to be unmunged.
1183
 *
1184
 * @return
1185
 *   An unmunged filename string.
1186
 */
1187
function file_unmunge_filename($filename) {
1188
  return str_replace('_.', '.', $filename);
1189
}
1190

    
1191
/**
1192
 * Creates a full file path from a directory and filename.
1193
 *
1194
 * If a file with the specified name already exists, an alternative will be
1195
 * used.
1196
 *
1197
 * @param $basename
1198
 *   String filename
1199
 * @param $directory
1200
 *   String containing the directory or parent URI.
1201
 *
1202
 * @return
1203
 *   File path consisting of $directory and a unique filename based off
1204
 *   of $basename.
1205
 */
1206
function file_create_filename($basename, $directory) {
1207
  // Strip control characters (ASCII value < 32). Though these are allowed in
1208
  // some filesystems, not many applications handle them well.
1209
  $basename = preg_replace('/[\x00-\x1F]/u', '_', $basename);
1210
  if (substr(PHP_OS, 0, 3) == 'WIN') {
1211
    // These characters are not allowed in Windows filenames
1212
    $basename = str_replace(array(':', '*', '?', '"', '<', '>', '|'), '_', $basename);
1213
  }
1214

    
1215
  // A URI or path may already have a trailing slash or look like "public://".
1216
  if (substr($directory, -1) == '/') {
1217
    $separator = '';
1218
  }
1219
  else {
1220
    $separator = '/';
1221
  }
1222

    
1223
  $destination = $directory . $separator . $basename;
1224

    
1225
  if (file_exists($destination)) {
1226
    // Destination file already exists, generate an alternative.
1227
    $pos = strrpos($basename, '.');
1228
    if ($pos !== FALSE) {
1229
      $name = substr($basename, 0, $pos);
1230
      $ext = substr($basename, $pos);
1231
    }
1232
    else {
1233
      $name = $basename;
1234
      $ext = '';
1235
    }
1236

    
1237
    $counter = 0;
1238
    do {
1239
      $destination = $directory . $separator . $name . '_' . $counter++ . $ext;
1240
    } while (file_exists($destination));
1241
  }
1242

    
1243
  return $destination;
1244
}
1245

    
1246
/**
1247
 * Deletes a file and its database record.
1248
 *
1249
 * If the $force parameter is not TRUE, file_usage_list() will be called to
1250
 * determine if the file is being used by any modules. If the file is being
1251
 * used the delete will be canceled.
1252
 *
1253
 * @param $file
1254
 *   A file object.
1255
 * @param $force
1256
 *   Boolean indicating that the file should be deleted even if the file is
1257
 *   reported as in use by the file_usage table.
1258
 *
1259
 * @return mixed
1260
 *   TRUE for success, FALSE in the event of an error, or an array if the file
1261
 *   is being used by any modules.
1262
 *
1263
 * @see file_unmanaged_delete()
1264
 * @see file_usage_list()
1265
 * @see file_usage_delete()
1266
 * @see hook_file_delete()
1267
 */
1268
function file_delete(stdClass $file, $force = FALSE) {
1269
  if (!file_valid_uri($file->uri)) {
1270
    if (($realpath = drupal_realpath($file->uri)) !== FALSE) {
1271
      watchdog('file', 'File %file (%realpath) could not be deleted because it is not a valid URI. This may be caused by improper use of file_delete() or a missing stream wrapper.', array('%file' => $file->uri, '%realpath' => $realpath));
1272
    }
1273
    else {
1274
      watchdog('file', 'File %file could not be deleted because it is not a valid URI. This may be caused by improper use of file_delete() or a missing stream wrapper.', array('%file' => $file->uri));
1275
    }
1276
    drupal_set_message(t('The specified file %file could not be deleted, because it is not a valid URI. More information is available in the system log.', array('%file' => $file->uri)), 'error');
1277
    return FALSE;
1278
  }
1279

    
1280
  // If any module still has a usage entry in the file_usage table, the file
1281
  // will not be deleted, but file_delete() will return a populated array
1282
  // that tests as TRUE.
1283
  if (!$force && ($references = file_usage_list($file))) {
1284
    return $references;
1285
  }
1286

    
1287
  // Let other modules clean up any references to the deleted file.
1288
  module_invoke_all('file_delete', $file);
1289
  module_invoke_all('entity_delete', $file, 'file');
1290

    
1291
  // Make sure the file is deleted before removing its row from the
1292
  // database, so UIs can still find the file in the database.
1293
  if (file_unmanaged_delete($file->uri)) {
1294
    db_delete('file_managed')->condition('fid', $file->fid)->execute();
1295
    db_delete('file_usage')->condition('fid', $file->fid)->execute();
1296
    return TRUE;
1297
  }
1298
  return FALSE;
1299
}
1300

    
1301
/**
1302
 * Deletes a file without database changes or hook invocations.
1303
 *
1304
 * This function should be used when the file to be deleted does not have an
1305
 * entry recorded in the files table.
1306
 *
1307
 * @param $path
1308
 *   A string containing a file path or (streamwrapper) URI.
1309
 *
1310
 * @return
1311
 *   TRUE for success or path does not exist, or FALSE in the event of an
1312
 *   error.
1313
 *
1314
 * @see file_delete()
1315
 * @see file_unmanaged_delete_recursive()
1316
 */
1317
function file_unmanaged_delete($path) {
1318
  if (is_dir($path)) {
1319
    watchdog('file', '%path is a directory and cannot be removed using file_unmanaged_delete().', array('%path' => $path), WATCHDOG_ERROR);
1320
    return FALSE;
1321
  }
1322
  if (is_file($path)) {
1323
    return drupal_unlink($path);
1324
  }
1325
  // Return TRUE for non-existent file, but log that nothing was actually
1326
  // deleted, as the current state is the intended result.
1327
  if (!file_exists($path)) {
1328
    watchdog('file', 'The file %path was not deleted, because it does not exist.', array('%path' => $path), WATCHDOG_NOTICE);
1329
    return TRUE;
1330
  }
1331
  // We cannot handle anything other than files and directories. Log an error
1332
  // for everything else (sockets, symbolic links, etc).
1333
  watchdog('file', 'The file %path is not of a recognized type so it was not deleted.', array('%path' => $path), WATCHDOG_ERROR);
1334
  return FALSE;
1335
}
1336

    
1337
/**
1338
 * Deletes all files and directories in the specified filepath recursively.
1339
 *
1340
 * If the specified path is a directory then the function will call itself
1341
 * recursively to process the contents. Once the contents have been removed the
1342
 * directory will also be removed.
1343
 *
1344
 * If the specified path is a file then it will be passed to
1345
 * file_unmanaged_delete().
1346
 *
1347
 * Note that this only deletes visible files with write permission.
1348
 *
1349
 * @param $path
1350
 *   A string containing either an URI or a file or directory path.
1351
 *
1352
 * @return
1353
 *   TRUE for success or if path does not exist, FALSE in the event of an
1354
 *   error.
1355
 *
1356
 * @see file_unmanaged_delete()
1357
 */
1358
function file_unmanaged_delete_recursive($path) {
1359
  if (is_dir($path)) {
1360
    $dir = dir($path);
1361
    while (($entry = $dir->read()) !== FALSE) {
1362
      if ($entry == '.' || $entry == '..') {
1363
        continue;
1364
      }
1365
      $entry_path = $path . '/' . $entry;
1366
      file_unmanaged_delete_recursive($entry_path);
1367
    }
1368
    $dir->close();
1369

    
1370
    return drupal_rmdir($path);
1371
  }
1372
  return file_unmanaged_delete($path);
1373
}
1374

    
1375
/**
1376
 * Determines total disk space used by a single user or the whole filesystem.
1377
 *
1378
 * @param $uid
1379
 *   Optional. A user id, specifying NULL returns the total space used by all
1380
 *   non-temporary files.
1381
 * @param $status
1382
 *   Optional. The file status to consider. The default is to only
1383
 *   consider files in status FILE_STATUS_PERMANENT.
1384
 *
1385
 * @return
1386
 *   An integer containing the number of bytes used.
1387
 */
1388
function file_space_used($uid = NULL, $status = FILE_STATUS_PERMANENT) {
1389
  $query = db_select('file_managed', 'f');
1390
  $query->condition('f.status', $status);
1391
  $query->addExpression('SUM(f.filesize)', 'filesize');
1392
  if (isset($uid)) {
1393
    $query->condition('f.uid', $uid);
1394
  }
1395
  return $query->execute()->fetchField();
1396
}
1397

    
1398
/**
1399
 * Saves a file upload to a new location.
1400
 *
1401
 * The file will be added to the {file_managed} table as a temporary file.
1402
 * Temporary files are periodically cleaned. To make the file a permanent file,
1403
 * assign the status and use file_save() to save the changes.
1404
 *
1405
 * @param $source
1406
 *   A string specifying the filepath or URI of the uploaded file to save.
1407
 * @param $validators
1408
 *   An optional, associative array of callback functions used to validate the
1409
 *   file. See file_validate() for a full discussion of the array format.
1410
 *   If no extension validator is provided it will default to a limited safe
1411
 *   list of extensions which is as follows: "jpg jpeg gif png txt
1412
 *   doc xls pdf ppt pps odt ods odp". To allow all extensions you must
1413
 *   explicitly set the 'file_validate_extensions' validator to an empty array
1414
 *   (Beware: this is not safe and should only be allowed for trusted users, if
1415
 *   at all).
1416
 * @param $destination
1417
 *   A string containing the URI $source should be copied to.
1418
 *   This must be a stream wrapper URI. If this value is omitted, Drupal's
1419
 *   temporary files scheme will be used ("temporary://").
1420
 * @param $replace
1421
 *   Replace behavior when the destination file already exists:
1422
 *   - FILE_EXISTS_REPLACE: Replace the existing file.
1423
 *   - FILE_EXISTS_RENAME: Append _{incrementing number} until the filename is
1424
 *     unique.
1425
 *   - FILE_EXISTS_ERROR: Do nothing and return FALSE.
1426
 *
1427
 * @return
1428
 *   An object containing the file information if the upload succeeded, FALSE
1429
 *   in the event of an error, or NULL if no file was uploaded. The
1430
 *   documentation for the "File interface" group, which you can find under
1431
 *   Related topics, or the header at the top of this file, documents the
1432
 *   components of a file object. In addition to the standard components,
1433
 *   this function adds:
1434
 *   - source: Path to the file before it is moved.
1435
 *   - destination: Path to the file after it is moved (same as 'uri').
1436
 */
1437
function file_save_upload($source, $validators = array(), $destination = FALSE, $replace = FILE_EXISTS_RENAME) {
1438
  global $user;
1439
  static $upload_cache;
1440

    
1441
  // Return cached objects without processing since the file will have
1442
  // already been processed and the paths in _FILES will be invalid.
1443
  if (isset($upload_cache[$source])) {
1444
    return $upload_cache[$source];
1445
  }
1446

    
1447
  // Make sure there's an upload to process.
1448
  if (empty($_FILES['files']['name'][$source])) {
1449
    return NULL;
1450
  }
1451

    
1452
  // Check for file upload errors and return FALSE if a lower level system
1453
  // error occurred. For a complete list of errors:
1454
  // See http://php.net/manual/features.file-upload.errors.php.
1455
  switch ($_FILES['files']['error'][$source]) {
1456
    case UPLOAD_ERR_INI_SIZE:
1457
    case UPLOAD_ERR_FORM_SIZE:
1458
      drupal_set_message(t('The file %file could not be saved, because it exceeds %maxsize, the maximum allowed size for uploads.', array('%file' => $_FILES['files']['name'][$source], '%maxsize' => format_size(file_upload_max_size()))), 'error');
1459
      return FALSE;
1460

    
1461
    case UPLOAD_ERR_PARTIAL:
1462
    case UPLOAD_ERR_NO_FILE:
1463
      drupal_set_message(t('The file %file could not be saved, because the upload did not complete.', array('%file' => $_FILES['files']['name'][$source])), 'error');
1464
      return FALSE;
1465

    
1466
    case UPLOAD_ERR_OK:
1467
      // Final check that this is a valid upload, if it isn't, use the
1468
      // default error handler.
1469
      if (is_uploaded_file($_FILES['files']['tmp_name'][$source])) {
1470
        break;
1471
      }
1472

    
1473
    // Unknown error
1474
    default:
1475
      drupal_set_message(t('The file %file could not be saved. An unknown error has occurred.', array('%file' => $_FILES['files']['name'][$source])), 'error');
1476
      return FALSE;
1477
  }
1478

    
1479
  // Begin building file object.
1480
  $file = new stdClass();
1481
  $file->uid      = $user->uid;
1482
  $file->status   = 0;
1483
  $file->filename = trim(drupal_basename($_FILES['files']['name'][$source]), '.');
1484
  $file->uri      = $_FILES['files']['tmp_name'][$source];
1485
  $file->filemime = file_get_mimetype($file->filename);
1486
  $file->filesize = $_FILES['files']['size'][$source];
1487

    
1488
  $extensions = '';
1489
  if (isset($validators['file_validate_extensions'])) {
1490
    if (isset($validators['file_validate_extensions'][0])) {
1491
      // Build the list of non-munged extensions if the caller provided them.
1492
      $extensions = $validators['file_validate_extensions'][0];
1493
    }
1494
    else {
1495
      // If 'file_validate_extensions' is set and the list is empty then the
1496
      // caller wants to allow any extension. In this case we have to remove the
1497
      // validator or else it will reject all extensions.
1498
      unset($validators['file_validate_extensions']);
1499
    }
1500
  }
1501
  else {
1502
    // No validator was provided, so add one using the default list.
1503
    // Build a default non-munged safe list for file_munge_filename().
1504
    $extensions = 'jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp';
1505
    $validators['file_validate_extensions'] = array();
1506
    $validators['file_validate_extensions'][0] = $extensions;
1507
  }
1508

    
1509
  if (!empty($extensions)) {
1510
    // Munge the filename to protect against possible malicious extension hiding
1511
    // within an unknown file type (ie: filename.html.foo).
1512
    $file->filename = file_munge_filename($file->filename, $extensions);
1513
  }
1514

    
1515
  // Rename potentially executable files, to help prevent exploits (i.e. will
1516
  // rename filename.php.foo and filename.php to filename.php.foo.txt and
1517
  // filename.php.txt, respectively). Don't rename if 'allow_insecure_uploads'
1518
  // evaluates to TRUE.
1519
  if (!variable_get('allow_insecure_uploads', 0) && preg_match('/\.(php|pl|py|cgi|asp|js)(\.|$)/i', $file->filename) && (substr($file->filename, -4) != '.txt')) {
1520
    $file->filemime = 'text/plain';
1521
    $file->uri .= '.txt';
1522
    $file->filename .= '.txt';
1523
    // The .txt extension may not be in the allowed list of extensions. We have
1524
    // to add it here or else the file upload will fail.
1525
    if (!empty($extensions)) {
1526
      $validators['file_validate_extensions'][0] .= ' txt';
1527
      drupal_set_message(t('For security reasons, your upload has been renamed to %filename.', array('%filename' => $file->filename)));
1528
    }
1529
  }
1530

    
1531
  // If the destination is not provided, use the temporary directory.
1532
  if (empty($destination)) {
1533
    $destination = 'temporary://';
1534
  }
1535

    
1536
  // Assert that the destination contains a valid stream.
1537
  $destination_scheme = file_uri_scheme($destination);
1538
  if (!$destination_scheme || !file_stream_wrapper_valid_scheme($destination_scheme)) {
1539
    drupal_set_message(t('The file could not be uploaded, because the destination %destination is invalid.', array('%destination' => $destination)), 'error');
1540
    return FALSE;
1541
  }
1542

    
1543
  $file->source = $source;
1544
  // A URI may already have a trailing slash or look like "public://".
1545
  if (substr($destination, -1) != '/') {
1546
    $destination .= '/';
1547
  }
1548
  $file->destination = file_destination($destination . $file->filename, $replace);
1549
  // If file_destination() returns FALSE then $replace == FILE_EXISTS_ERROR and
1550
  // there's an existing file so we need to bail.
1551
  if ($file->destination === FALSE) {
1552
    drupal_set_message(t('The file %source could not be uploaded because a file by that name already exists in the destination %directory.', array('%source' => $source, '%directory' => $destination)), 'error');
1553
    return FALSE;
1554
  }
1555

    
1556
  // Add in our check of the the file name length.
1557
  $validators['file_validate_name_length'] = array();
1558

    
1559
  // Call the validation functions specified by this function's caller.
1560
  $errors = file_validate($file, $validators);
1561

    
1562
  // Check for errors.
1563
  if (!empty($errors)) {
1564
    $message = t('The specified file %name could not be uploaded.', array('%name' => $file->filename));
1565
    if (count($errors) > 1) {
1566
      $message .= theme('item_list', array('items' => $errors));
1567
    }
1568
    else {
1569
      $message .= ' ' . array_pop($errors);
1570
    }
1571
    form_set_error($source, $message);
1572
    return FALSE;
1573
  }
1574

    
1575
  // Move uploaded files from PHP's upload_tmp_dir to Drupal's temporary
1576
  // directory. This overcomes open_basedir restrictions for future file
1577
  // operations.
1578
  $file->uri = $file->destination;
1579
  if (!drupal_move_uploaded_file($_FILES['files']['tmp_name'][$source], $file->uri)) {
1580
    form_set_error($source, t('File upload error. Could not move uploaded file.'));
1581
    watchdog('file', 'Upload error. Could not move uploaded file %file to destination %destination.', array('%file' => $file->filename, '%destination' => $file->uri));
1582
    return FALSE;
1583
  }
1584

    
1585
  // Set the permissions on the new file.
1586
  drupal_chmod($file->uri);
1587

    
1588
  // If we are replacing an existing file re-use its database record.
1589
  if ($replace == FILE_EXISTS_REPLACE) {
1590
    $existing_files = file_load_multiple(array(), array('uri' => $file->uri));
1591
    if (count($existing_files)) {
1592
      $existing = reset($existing_files);
1593
      $file->fid = $existing->fid;
1594
    }
1595
  }
1596

    
1597
  // If we made it this far it's safe to record this file in the database.
1598
  if ($file = file_save($file)) {
1599
    // Add file to the cache.
1600
    $upload_cache[$source] = $file;
1601
    return $file;
1602
  }
1603
  return FALSE;
1604
}
1605

    
1606
/**
1607
 * Moves an uploaded file to a new location.
1608
 *
1609
 * PHP's move_uploaded_file() does not properly support streams if safe_mode
1610
 * or open_basedir are enabled, so this function fills that gap.
1611
 *
1612
 * Compatibility: normal paths and stream wrappers.
1613
 *
1614
 * @param $filename
1615
 *   The filename of the uploaded file.
1616
 * @param $uri
1617
 *   A string containing the destination URI of the file.
1618
 *
1619
 * @return
1620
 *   TRUE on success, or FALSE on failure.
1621
 *
1622
 * @see move_uploaded_file()
1623
 * @see http://drupal.org/node/515192
1624
 * @ingroup php_wrappers
1625
 */
1626
function drupal_move_uploaded_file($filename, $uri) {
1627
  $result = @move_uploaded_file($filename, $uri);
1628
  // PHP's move_uploaded_file() does not properly support streams if safe_mode
1629
  // or open_basedir are enabled so if the move failed, try finding a real path
1630
  // and retry the move operation.
1631
  if (!$result) {
1632
    if ($realpath = drupal_realpath($uri)) {
1633
      $result = move_uploaded_file($filename, $realpath);
1634
    }
1635
    else {
1636
      $result = move_uploaded_file($filename, $uri);
1637
    }
1638
  }
1639

    
1640
  return $result;
1641
}
1642

    
1643
/**
1644
 * Checks that a file meets the criteria specified by the validators.
1645
 *
1646
 * After executing the validator callbacks specified hook_file_validate() will
1647
 * also be called to allow other modules to report errors about the file.
1648
 *
1649
 * @param $file
1650
 *   A Drupal file object.
1651
 * @param $validators
1652
 *   An optional, associative array of callback functions used to validate the
1653
 *   file. The keys are function names and the values arrays of callback
1654
 *   parameters which will be passed in after the file object. The
1655
 *   functions should return an array of error messages; an empty array
1656
 *   indicates that the file passed validation. The functions will be called in
1657
 *   the order specified.
1658
 *
1659
 * @return
1660
 *   An array containing validation error messages.
1661
 *
1662
 * @see hook_file_validate()
1663
 */
1664
function file_validate(stdClass &$file, $validators = array()) {
1665
  // Call the validation functions specified by this function's caller.
1666
  $errors = array();
1667
  foreach ($validators as $function => $args) {
1668
    if (function_exists($function)) {
1669
      array_unshift($args, $file);
1670
      $errors = array_merge($errors, call_user_func_array($function, $args));
1671
    }
1672
  }
1673

    
1674
  // Let other modules perform validation on the new file.
1675
  return array_merge($errors, module_invoke_all('file_validate', $file));
1676
}
1677

    
1678
/**
1679
 * Checks for files with names longer than we can store in the database.
1680
 *
1681
 * @param $file
1682
 *   A Drupal file object.
1683
 *
1684
 * @return
1685
 *   An array. If the file name is too long, it will contain an error message.
1686
 */
1687
function file_validate_name_length(stdClass $file) {
1688
  $errors = array();
1689

    
1690
  if (empty($file->filename)) {
1691
    $errors[] = t("The file's name is empty. Please give a name to the file.");
1692
  }
1693
  if (strlen($file->filename) > 240) {
1694
    $errors[] = t("The file's name exceeds the 240 characters limit. Please rename the file and try again.");
1695
  }
1696
  return $errors;
1697
}
1698

    
1699
/**
1700
 * Checks that the filename ends with an allowed extension.
1701
 *
1702
 * @param $file
1703
 *   A Drupal file object.
1704
 * @param $extensions
1705
 *   A string with a space separated list of allowed extensions.
1706
 *
1707
 * @return
1708
 *   An array. If the file extension is not allowed, it will contain an error
1709
 *   message.
1710
 *
1711
 * @see hook_file_validate()
1712
 */
1713
function file_validate_extensions(stdClass $file, $extensions) {
1714
  $errors = array();
1715

    
1716
  $regex = '/\.(' . preg_replace('/ +/', '|', preg_quote($extensions)) . ')$/i';
1717
  if (!preg_match($regex, $file->filename)) {
1718
    $errors[] = t('Only files with the following extensions are allowed: %files-allowed.', array('%files-allowed' => $extensions));
1719
  }
1720
  return $errors;
1721
}
1722

    
1723
/**
1724
 * Checks that the file's size is below certain limits.
1725
 *
1726
 * This check is not enforced for the user #1.
1727
 *
1728
 * @param $file
1729
 *   A Drupal file object.
1730
 * @param $file_limit
1731
 *   An integer specifying the maximum file size in bytes. Zero indicates that
1732
 *   no limit should be enforced.
1733
 * @param $user_limit
1734
 *   An integer specifying the maximum number of bytes the user is allowed.
1735
 *   Zero indicates that no limit should be enforced.
1736
 *
1737
 * @return
1738
 *   An array. If the file size exceeds limits, it will contain an error
1739
 *   message.
1740
 *
1741
 * @see hook_file_validate()
1742
 */
1743
function file_validate_size(stdClass $file, $file_limit = 0, $user_limit = 0) {
1744
  global $user;
1745

    
1746
  $errors = array();
1747

    
1748
  // Bypass validation for uid  = 1.
1749
  if ($user->uid != 1) {
1750
    if ($file_limit && $file->filesize > $file_limit) {
1751
      $errors[] = t('The file is %filesize exceeding the maximum file size of %maxsize.', array('%filesize' => format_size($file->filesize), '%maxsize' => format_size($file_limit)));
1752
    }
1753

    
1754
    // Save a query by only calling file_space_used() when a limit is provided.
1755
    if ($user_limit && (file_space_used($user->uid) + $file->filesize) > $user_limit) {
1756
      $errors[] = t('The file is %filesize which would exceed your disk quota of %quota.', array('%filesize' => format_size($file->filesize), '%quota' => format_size($user_limit)));
1757
    }
1758
  }
1759
  return $errors;
1760
}
1761

    
1762
/**
1763
 * Checks that the file is recognized by image_get_info() as an image.
1764
 *
1765
 * @param $file
1766
 *   A Drupal file object.
1767
 *
1768
 * @return
1769
 *   An array. If the file is not an image, it will contain an error message.
1770
 *
1771
 * @see hook_file_validate()
1772
 */
1773
function file_validate_is_image(stdClass $file) {
1774
  $errors = array();
1775

    
1776
  $info = image_get_info($file->uri);
1777
  if (!$info || empty($info['extension'])) {
1778
    $errors[] = t('Only JPEG, PNG and GIF images are allowed.');
1779
  }
1780

    
1781
  return $errors;
1782
}
1783

    
1784
/**
1785
 * Verifies that image dimensions are within the specified maximum and minimum.
1786
 *
1787
 * Non-image files will be ignored. If a image toolkit is available the image
1788
 * will be scaled to fit within the desired maximum dimensions.
1789
 *
1790
 * @param $file
1791
 *   A Drupal file object. This function may resize the file affecting its
1792
 *   size.
1793
 * @param $maximum_dimensions
1794
 *   An optional string in the form WIDTHxHEIGHT e.g. '640x480' or '85x85'. If
1795
 *   an image toolkit is installed the image will be resized down to these
1796
 *   dimensions. A value of 0 indicates no restriction on size, so resizing
1797
 *   will be attempted.
1798
 * @param $minimum_dimensions
1799
 *   An optional string in the form WIDTHxHEIGHT. This will check that the
1800
 *   image meets a minimum size. A value of 0 indicates no restriction.
1801
 *
1802
 * @return
1803
 *   An array. If the file is an image and did not meet the requirements, it
1804
 *   will contain an error message.
1805
 *
1806
 * @see hook_file_validate()
1807
 */
1808
function file_validate_image_resolution(stdClass $file, $maximum_dimensions = 0, $minimum_dimensions = 0) {
1809
  $errors = array();
1810

    
1811
  // Check first that the file is an image.
1812
  if ($info = image_get_info($file->uri)) {
1813
    if ($maximum_dimensions) {
1814
      // Check that it is smaller than the given dimensions.
1815
      list($width, $height) = explode('x', $maximum_dimensions);
1816
      if ($info['width'] > $width || $info['height'] > $height) {
1817
        // Try to resize the image to fit the dimensions.
1818
        if ($image = image_load($file->uri)) {
1819
          image_scale($image, $width, $height);
1820
          image_save($image);
1821
          $file->filesize = $image->info['file_size'];
1822
          drupal_set_message(t('The image was resized to fit within the maximum allowed dimensions of %dimensions pixels.', array('%dimensions' => $maximum_dimensions)));
1823
        }
1824
        else {
1825
          $errors[] = t('The image is too large; the maximum dimensions are %dimensions pixels.', array('%dimensions' => $maximum_dimensions));
1826
        }
1827
      }
1828
    }
1829

    
1830
    if ($minimum_dimensions) {
1831
      // Check that it is larger than the given dimensions.
1832
      list($width, $height) = explode('x', $minimum_dimensions);
1833
      if ($info['width'] < $width || $info['height'] < $height) {
1834
        $errors[] = t('The image is too small; the minimum dimensions are %dimensions pixels.', array('%dimensions' => $minimum_dimensions));
1835
      }
1836
    }
1837
  }
1838

    
1839
  return $errors;
1840
}
1841

    
1842
/**
1843
 * Saves a file to the specified destination and creates a database entry.
1844
 *
1845
 * @param $data
1846
 *   A string containing the contents of the file.
1847
 * @param $destination
1848
 *   A string containing the destination URI. This must be a stream wrapper URI.
1849
 *   If no value is provided, a randomized name will be generated and the file
1850
 *   will be saved using Drupal's default files scheme, usually "public://".
1851
 * @param $replace
1852
 *   Replace behavior when the destination file already exists:
1853
 *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
1854
 *       the destination name exists then its database entry will be updated. If
1855
 *       no database entry is found then a new one will be created.
1856
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
1857
 *       unique.
1858
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
1859
 *
1860
 * @return
1861
 *   A file object, or FALSE on error.
1862
 *
1863
 * @see file_unmanaged_save_data()
1864
 */
1865
function file_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
1866
  global $user;
1867

    
1868
  if (empty($destination)) {
1869
    $destination = file_default_scheme() . '://';
1870
  }
1871
  if (!file_valid_uri($destination)) {
1872
    watchdog('file', 'The data could not be saved because the destination %destination is invalid. This may be caused by improper use of file_save_data() or a missing stream wrapper.', array('%destination' => $destination));
1873
    drupal_set_message(t('The data could not be saved, because the destination is invalid. More information is available in the system log.'), 'error');
1874
    return FALSE;
1875
  }
1876

    
1877
  if ($uri = file_unmanaged_save_data($data, $destination, $replace)) {
1878
    // Create a file object.
1879
    $file = new stdClass();
1880
    $file->fid = NULL;
1881
    $file->uri = $uri;
1882
    $file->filename = drupal_basename($uri);
1883
    $file->filemime = file_get_mimetype($file->uri);
1884
    $file->uid      = $user->uid;
1885
    $file->status   = FILE_STATUS_PERMANENT;
1886
    // If we are replacing an existing file re-use its database record.
1887
    if ($replace == FILE_EXISTS_REPLACE) {
1888
      $existing_files = file_load_multiple(array(), array('uri' => $uri));
1889
      if (count($existing_files)) {
1890
        $existing = reset($existing_files);
1891
        $file->fid = $existing->fid;
1892
        $file->filename = $existing->filename;
1893
      }
1894
    }
1895
    // If we are renaming around an existing file (rather than a directory),
1896
    // use its basename for the filename.
1897
    elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
1898
      $file->filename = drupal_basename($destination);
1899
    }
1900

    
1901
    return file_save($file);
1902
  }
1903
  return FALSE;
1904
}
1905

    
1906
/**
1907
 * Saves a string to the specified destination without invoking file API.
1908
 *
1909
 * This function is identical to file_save_data() except the file will not be
1910
 * saved to the {file_managed} table and none of the file_* hooks will be
1911
 * called.
1912
 *
1913
 * @param $data
1914
 *   A string containing the contents of the file.
1915
 * @param $destination
1916
 *   A string containing the destination location. This must be a stream wrapper
1917
 *   URI. If no value is provided, a randomized name will be generated and the
1918
 *   file will be saved using Drupal's default files scheme, usually
1919
 *   "public://".
1920
 * @param $replace
1921
 *   Replace behavior when the destination file already exists:
1922
 *   - FILE_EXISTS_REPLACE - Replace the existing file.
1923
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
1924
 *                          unique.
1925
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
1926
 *
1927
 * @return
1928
 *   A string with the path of the resulting file, or FALSE on error.
1929
 *
1930
 * @see file_save_data()
1931
 */
1932
function file_unmanaged_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
1933
  // Write the data to a temporary file.
1934
  $temp_name = drupal_tempnam('temporary://', 'file');
1935
  if (file_put_contents($temp_name, $data) === FALSE) {
1936
    drupal_set_message(t('The file could not be created.'), 'error');
1937
    return FALSE;
1938
  }
1939

    
1940
  // Move the file to its final destination.
1941
  return file_unmanaged_move($temp_name, $destination, $replace);
1942
}
1943

    
1944
/**
1945
 * Transfers a file to the client using HTTP.
1946
 *
1947
 * Pipes a file through Drupal to the client.
1948
 *
1949
 * @param $uri
1950
 *   String specifying the file URI to transfer.
1951
 * @param $headers
1952
 *   An array of HTTP headers to send along with file.
1953
 */
1954
function file_transfer($uri, $headers) {
1955
  if (ob_get_level()) {
1956
    ob_end_clean();
1957
  }
1958

    
1959
  foreach ($headers as $name => $value) {
1960
    drupal_add_http_header($name, $value);
1961
  }
1962
  drupal_send_headers();
1963
  $scheme = file_uri_scheme($uri);
1964
  // Transfer file in 1024 byte chunks to save memory usage.
1965
  if ($scheme && file_stream_wrapper_valid_scheme($scheme) && $fd = fopen($uri, 'rb')) {
1966
    while (!feof($fd)) {
1967
      print fread($fd, 1024);
1968
    }
1969
    fclose($fd);
1970
  }
1971
  else {
1972
    drupal_not_found();
1973
  }
1974
  drupal_exit();
1975
}
1976

    
1977
/**
1978
 * Menu handler for private file transfers.
1979
 *
1980
 * Call modules that implement hook_file_download() to find out if a file is
1981
 * accessible and what headers it should be transferred with. If one or more
1982
 * modules returned headers the download will start with the returned headers.
1983
 * If a module returns -1 drupal_access_denied() will be returned. If the file
1984
 * exists but no modules responded drupal_access_denied() will be returned.
1985
 * If the file does not exist drupal_not_found() will be returned.
1986
 *
1987
 * @see system_menu()
1988
 */
1989
function file_download() {
1990
  // Merge remainder of arguments from GET['q'], into relative file path.
1991
  $args = func_get_args();
1992
  $scheme = array_shift($args);
1993
  $target = implode('/', $args);
1994
  $uri = $scheme . '://' . $target;
1995
  if (file_stream_wrapper_valid_scheme($scheme) && file_exists($uri)) {
1996
    // Let other modules provide headers and controls access to the file.
1997
    // module_invoke_all() uses array_merge_recursive() which merges header
1998
    // values into a new array. To avoid that and allow modules to override
1999
    // headers instead, use array_merge() to merge the returned arrays.
2000
    $headers = array();
2001
    foreach (module_implements('file_download') as $module) {
2002
      $function = $module . '_file_download';
2003
      $result = $function($uri);
2004
      if ($result == -1) {
2005
        // Throw away the headers received so far.
2006
        $headers = array();
2007
        break;
2008
      }
2009
      if (isset($result) && is_array($result)) {
2010
        $headers = array_merge($headers, $result);
2011
      }
2012
    }
2013
    if (count($headers)) {
2014
      file_transfer($uri, $headers);
2015
    }
2016
    drupal_access_denied();
2017
  }
2018
  else {
2019
    drupal_not_found();
2020
  }
2021
  drupal_exit();
2022
}
2023

    
2024

    
2025
/**
2026
 * Finds all files that match a given mask in a given directory.
2027
 *
2028
 * Directories and files beginning with a period are excluded; this
2029
 * prevents hidden files and directories (such as SVN working directories)
2030
 * from being scanned.
2031
 *
2032
 * @param $dir
2033
 *   The base directory or URI to scan, without trailing slash.
2034
 * @param $mask
2035
 *   The preg_match() regular expression of the files to find.
2036
 * @param $options
2037
 *   An associative array of additional options, with the following elements:
2038
 *   - 'nomask': The preg_match() regular expression of the files to ignore.
2039
 *     Defaults to '/(\.\.?|CVS)$/'.
2040
 *   - 'callback': The callback function to call for each match. There is no
2041
 *     default callback.
2042
 *   - 'recurse': When TRUE, the directory scan will recurse the entire tree
2043
 *     starting at the provided directory. Defaults to TRUE.
2044
 *   - 'key': The key to be used for the returned associative array of files.
2045
 *     Possible values are 'uri', for the file's URI; 'filename', for the
2046
 *     basename of the file; and 'name' for the name of the file without the
2047
 *     extension. Defaults to 'uri'.
2048
 *   - 'min_depth': Minimum depth of directories to return files from. Defaults
2049
 *     to 0.
2050
 * @param $depth
2051
 *   Current depth of recursion. This parameter is only used internally and
2052
 *   should not be passed in.
2053
 *
2054
 * @return
2055
 *   An associative array (keyed on the chosen key) of objects with 'uri',
2056
 *   'filename', and 'name' members corresponding to the matching files.
2057
 */
2058
function file_scan_directory($dir, $mask, $options = array(), $depth = 0) {
2059
  // Merge in defaults.
2060
  $options += array(
2061
    'nomask' => '/(\.\.?|CVS)$/',
2062
    'callback' => 0,
2063
    'recurse' => TRUE,
2064
    'key' => 'uri',
2065
    'min_depth' => 0,
2066
  );
2067

    
2068
  $options['key'] = in_array($options['key'], array('uri', 'filename', 'name')) ? $options['key'] : 'uri';
2069
  $files = array();
2070
  if (is_dir($dir) && $handle = opendir($dir)) {
2071
    while (FALSE !== ($filename = readdir($handle))) {
2072
      if (!preg_match($options['nomask'], $filename) && $filename[0] != '.') {
2073
        $uri = "$dir/$filename";
2074
        $uri = file_stream_wrapper_uri_normalize($uri);
2075
        if (is_dir($uri) && $options['recurse']) {
2076
          // Give priority to files in this folder by merging them in after any subdirectory files.
2077
          $files = array_merge(file_scan_directory($uri, $mask, $options, $depth + 1), $files);
2078
        }
2079
        elseif ($depth >= $options['min_depth'] && preg_match($mask, $filename)) {
2080
          // Always use this match over anything already set in $files with the
2081
          // same $$options['key'].
2082
          $file = new stdClass();
2083
          $file->uri = $uri;
2084
          $file->filename = $filename;
2085
          $file->name = pathinfo($filename, PATHINFO_FILENAME);
2086
          $key = $options['key'];
2087
          $files[$file->$key] = $file;
2088
          if ($options['callback']) {
2089
            $options['callback']($uri);
2090
          }
2091
        }
2092
      }
2093
    }
2094

    
2095
    closedir($handle);
2096
  }
2097

    
2098
  return $files;
2099
}
2100

    
2101
/**
2102
 * Determines the maximum file upload size by querying the PHP settings.
2103
 *
2104
 * @return
2105
 *   A file size limit in bytes based on the PHP upload_max_filesize and
2106
 *   post_max_size
2107
 */
2108
function file_upload_max_size() {
2109
  static $max_size = -1;
2110

    
2111
  if ($max_size < 0) {
2112
    // Start with post_max_size.
2113
    $max_size = parse_size(ini_get('post_max_size'));
2114

    
2115
    // If upload_max_size is less, then reduce. Except if upload_max_size is
2116
    // zero, which indicates no limit.
2117
    $upload_max = parse_size(ini_get('upload_max_filesize'));
2118
    if ($upload_max > 0 && $upload_max < $max_size) {
2119
      $max_size = $upload_max;
2120
    }
2121
  }
2122
  return $max_size;
2123
}
2124

    
2125
/**
2126
 * Determines an Internet Media Type or MIME type from a filename.
2127
 *
2128
 * @param $uri
2129
 *   A string containing the URI, path, or filename.
2130
 * @param $mapping
2131
 *   An optional map of extensions to their mimetypes, in the form:
2132
 *    - 'mimetypes': a list of mimetypes, keyed by an identifier,
2133
 *    - 'extensions': the mapping itself, an associative array in which
2134
 *      the key is the extension (lowercase) and the value is the mimetype
2135
 *      identifier. If $mapping is NULL file_mimetype_mapping() is called.
2136
 *
2137
 * @return
2138
 *   The internet media type registered for the extension or
2139
 *   application/octet-stream for unknown extensions.
2140
 *
2141
 * @see file_default_mimetype_mapping()
2142
 */
2143
function file_get_mimetype($uri, $mapping = NULL) {
2144
  if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
2145
    return $wrapper->getMimeType($uri, $mapping);
2146
  }
2147
  else {
2148
    // getMimeType() is not implementation specific, so we can directly
2149
    // call it without an instance.
2150
    return DrupalLocalStreamWrapper::getMimeType($uri, $mapping);
2151
  }
2152
}
2153

    
2154
/**
2155
 * Sets the permissions on a file or directory.
2156
 *
2157
 * This function will use the 'file_chmod_directory' and 'file_chmod_file'
2158
 * variables for the default modes for directories and uploaded/generated
2159
 * files. By default these will give everyone read access so that users
2160
 * accessing the files with a user account without the webserver group (e.g.
2161
 * via FTP) can read these files, and give group write permissions so webserver
2162
 * group members (e.g. a vhost account) can alter files uploaded and owned by
2163
 * the webserver.
2164
 *
2165
 * PHP's chmod does not support stream wrappers so we use our wrapper
2166
 * implementation which interfaces with chmod() by default. Contrib wrappers
2167
 * may override this behavior in their implementations as needed.
2168
 *
2169
 * @param $uri
2170
 *   A string containing a URI file, or directory path.
2171
 * @param $mode
2172
 *   Integer value for the permissions. Consult PHP chmod() documentation for
2173
 *   more information.
2174
 *
2175
 * @return
2176
 *   TRUE for success, FALSE in the event of an error.
2177
 *
2178
 * @ingroup php_wrappers
2179
 */
2180
function drupal_chmod($uri, $mode = NULL) {
2181
  if (!isset($mode)) {
2182
    if (is_dir($uri)) {
2183
      $mode = variable_get('file_chmod_directory', 0775);
2184
    }
2185
    else {
2186
      $mode = variable_get('file_chmod_file', 0664);
2187
    }
2188
  }
2189

    
2190
  // If this URI is a stream, pass it off to the appropriate stream wrapper.
2191
  // Otherwise, attempt PHP's chmod. This allows use of drupal_chmod even
2192
  // for unmanaged files outside of the stream wrapper interface.
2193
  if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
2194
    if ($wrapper->chmod($mode)) {
2195
      return TRUE;
2196
    }
2197
  }
2198
  else {
2199
    if (@chmod($uri, $mode)) {
2200
      return TRUE;
2201
    }
2202
  }
2203

    
2204
  watchdog('file', 'The file permissions could not be set on %uri.', array('%uri' => $uri), WATCHDOG_ERROR);
2205
  return FALSE;
2206
}
2207

    
2208
/**
2209
 * Deletes a file.
2210
 *
2211
 * PHP's unlink() is broken on Windows, as it can fail to remove a file
2212
 * when it has a read-only flag set.
2213
 *
2214
 * @param $uri
2215
 *   A URI or pathname.
2216
 * @param $context
2217
 *   Refer to http://php.net/manual/ref.stream.php
2218
 *
2219
 * @return
2220
 *   Boolean TRUE on success, or FALSE on failure.
2221
 *
2222
 * @see unlink()
2223
 * @ingroup php_wrappers
2224
 */
2225
function drupal_unlink($uri, $context = NULL) {
2226
  $scheme = file_uri_scheme($uri);
2227
  if ((!$scheme || !file_stream_wrapper_valid_scheme($scheme)) && (substr(PHP_OS, 0, 3) == 'WIN')) {
2228
    chmod($uri, 0600);
2229
  }
2230
  if ($context) {
2231
    return unlink($uri, $context);
2232
  }
2233
  else {
2234
    return unlink($uri);
2235
  }
2236
}
2237

    
2238
/**
2239
 * Resolves the absolute filepath of a local URI or filepath.
2240
 *
2241
 * The use of drupal_realpath() is discouraged, because it does not work for
2242
 * remote URIs. Except in rare cases, URIs should not be manually resolved.
2243
 *
2244
 * Only use this function if you know that the stream wrapper in the URI uses
2245
 * the local file system, and you need to pass an absolute path to a function
2246
 * that is incompatible with stream URIs.
2247
 *
2248
 * @param string $uri
2249
 *   A stream wrapper URI or a filepath, possibly including one or more symbolic
2250
 *   links.
2251
 *
2252
 * @return string|false
2253
 *   The absolute local filepath (with no symbolic links), or FALSE on failure.
2254
 *
2255
 * @see DrupalStreamWrapperInterface::realpath()
2256
 * @see http://php.net/manual/function.realpath.php
2257
 * @ingroup php_wrappers
2258
 */
2259
function drupal_realpath($uri) {
2260
  // If this URI is a stream, pass it off to the appropriate stream wrapper.
2261
  // Otherwise, attempt PHP's realpath. This allows use of drupal_realpath even
2262
  // for unmanaged files outside of the stream wrapper interface.
2263
  if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {
2264
    return $wrapper->realpath();
2265
  }
2266
  // Check that the URI has a value. There is a bug in PHP 5.2 on *BSD systems
2267
  // that makes realpath not return FALSE as expected when passing an empty
2268
  // variable.
2269
  // @todo Remove when Drupal drops support for PHP 5.2.
2270
  elseif (!empty($uri)) {
2271
    return realpath($uri);
2272
  }
2273
  return FALSE;
2274
}
2275

    
2276
/**
2277
 * Gets the name of the directory from a given path.
2278
 *
2279
 * PHP's dirname() does not properly pass streams, so this function fills
2280
 * that gap. It is backwards compatible with normal paths and will use
2281
 * PHP's dirname() as a fallback.
2282
 *
2283
 * Compatibility: normal paths and stream wrappers.
2284
 *
2285
 * @param $uri
2286
 *   A URI or path.
2287
 *
2288
 * @return
2289
 *   A string containing the directory name.
2290
 *
2291
 * @see dirname()
2292
 * @see http://drupal.org/node/515192
2293
 * @ingroup php_wrappers
2294
 */
2295
function drupal_dirname($uri) {
2296
  $scheme = file_uri_scheme($uri);
2297

    
2298
  if ($scheme && file_stream_wrapper_valid_scheme($scheme)) {
2299
    return file_stream_wrapper_get_instance_by_scheme($scheme)->dirname($uri);
2300
  }
2301
  else {
2302
    return dirname($uri);
2303
  }
2304
}
2305

    
2306
/**
2307
 * Gets the filename from a given path.
2308
 *
2309
 * PHP's basename() does not properly support streams or filenames beginning
2310
 * with a non-US-ASCII character.
2311
 *
2312
 * @see http://bugs.php.net/bug.php?id=37738
2313
 * @see basename()
2314
 *
2315
 * @ingroup php_wrappers
2316
 */
2317
function drupal_basename($uri, $suffix = NULL) {
2318
  $separators = '/';
2319
  if (DIRECTORY_SEPARATOR != '/') {
2320
    // For Windows OS add special separator.
2321
    $separators .= DIRECTORY_SEPARATOR;
2322
  }
2323
  // Remove right-most slashes when $uri points to directory.
2324
  $uri = rtrim($uri, $separators);
2325
  // Returns the trailing part of the $uri starting after one of the directory
2326
  // separators.
2327
  $filename = preg_match('@[^' . preg_quote($separators, '@') . ']+$@', $uri, $matches) ? $matches[0] : '';
2328
  // Cuts off a suffix from the filename.
2329
  if ($suffix) {
2330
    $filename = preg_replace('@' . preg_quote($suffix, '@') . '$@', '', $filename);
2331
  }
2332
  return $filename;
2333
}
2334

    
2335
/**
2336
 * Creates a directory using Drupal's default mode.
2337
 *
2338
 * PHP's mkdir() does not respect Drupal's default permissions mode. If a mode
2339
 * is not provided, this function will make sure that Drupal's is used.
2340
 *
2341
 * Compatibility: normal paths and stream wrappers.
2342
 *
2343
 * @param $uri
2344
 *   A URI or pathname.
2345
 * @param $mode
2346
 *   By default the Drupal mode is used.
2347
 * @param $recursive
2348
 *   Default to FALSE.
2349
 * @param $context
2350
 *   Refer to http://php.net/manual/ref.stream.php
2351
 *
2352
 * @return
2353
 *   Boolean TRUE on success, or FALSE on failure.
2354
 *
2355
 * @see mkdir()
2356
 * @see http://drupal.org/node/515192
2357
 * @ingroup php_wrappers
2358
 */
2359
function drupal_mkdir($uri, $mode = NULL, $recursive = FALSE, $context = NULL) {
2360
  if (!isset($mode)) {
2361
    $mode = variable_get('file_chmod_directory', 0775);
2362
  }
2363

    
2364
  if (!isset($context)) {
2365
    return mkdir($uri, $mode, $recursive);
2366
  }
2367
  else {
2368
    return mkdir($uri, $mode, $recursive, $context);
2369
  }
2370
}
2371

    
2372
/**
2373
 * Removes a directory.
2374
 *
2375
 * PHP's rmdir() is broken on Windows, as it can fail to remove a directory
2376
 * when it has a read-only flag set.
2377
 *
2378
 * @param $uri
2379
 *   A URI or pathname.
2380
 * @param $context
2381
 *   Refer to http://php.net/manual/ref.stream.php
2382
 *
2383
 * @return
2384
 *   Boolean TRUE on success, or FALSE on failure.
2385
 *
2386
 * @see rmdir()
2387
 * @ingroup php_wrappers
2388
 */
2389
function drupal_rmdir($uri, $context = NULL) {
2390
  $scheme = file_uri_scheme($uri);
2391
  if ((!$scheme || !file_stream_wrapper_valid_scheme($scheme)) && (substr(PHP_OS, 0, 3) == 'WIN')) {
2392
    chmod($uri, 0700);
2393
  }
2394
  if ($context) {
2395
    return rmdir($uri, $context);
2396
  }
2397
  else {
2398
    return rmdir($uri);
2399
  }
2400
}
2401

    
2402
/**
2403
 * Creates a file with a unique filename in the specified directory.
2404
 *
2405
 * PHP's tempnam() does not return a URI like we want. This function
2406
 * will return a URI if given a URI, or it will return a filepath if
2407
 * given a filepath.
2408
 *
2409
 * Compatibility: normal paths and stream wrappers.
2410
 *
2411
 * @param $directory
2412
 *   The directory where the temporary filename will be created.
2413
 * @param $prefix
2414
 *   The prefix of the generated temporary filename.
2415
 *   Note: Windows uses only the first three characters of prefix.
2416
 *
2417
 * @return
2418
 *   The new temporary filename, or FALSE on failure.
2419
 *
2420
 * @see tempnam()
2421
 * @see http://drupal.org/node/515192
2422
 * @ingroup php_wrappers
2423
 */
2424
function drupal_tempnam($directory, $prefix) {
2425
  $scheme = file_uri_scheme($directory);
2426

    
2427
  if ($scheme && file_stream_wrapper_valid_scheme($scheme)) {
2428
    $wrapper = file_stream_wrapper_get_instance_by_scheme($scheme);
2429

    
2430
    if ($filename = tempnam($wrapper->getDirectoryPath(), $prefix)) {
2431
      return $scheme . '://' . drupal_basename($filename);
2432
    }
2433
    else {
2434
      return FALSE;
2435
    }
2436
  }
2437
  else {
2438
    // Handle as a normal tempnam() call.
2439
    return tempnam($directory, $prefix);
2440
  }
2441
}
2442

    
2443
/**
2444
 * Gets the path of system-appropriate temporary directory.
2445
 */
2446
function file_directory_temp() {
2447
  $temporary_directory = variable_get('file_temporary_path', NULL);
2448

    
2449
  if (empty($temporary_directory)) {
2450
    $directories = array();
2451

    
2452
    // Has PHP been set with an upload_tmp_dir?
2453
    if (ini_get('upload_tmp_dir')) {
2454
      $directories[] = ini_get('upload_tmp_dir');
2455
    }
2456

    
2457
    // Operating system specific dirs.
2458
    if (substr(PHP_OS, 0, 3) == 'WIN') {
2459
      $directories[] = 'c:\\windows\\temp';
2460
      $directories[] = 'c:\\winnt\\temp';
2461
    }
2462
    else {
2463
      $directories[] = '/tmp';
2464
    }
2465
    // PHP may be able to find an alternative tmp directory.
2466
    // This function exists in PHP 5 >= 5.2.1, but Drupal
2467
    // requires PHP 5 >= 5.2.0, so we check for it.
2468
    if (function_exists('sys_get_temp_dir')) {
2469
      $directories[] = sys_get_temp_dir();
2470
    }
2471

    
2472
    foreach ($directories as $directory) {
2473
      if (is_dir($directory) && is_writable($directory)) {
2474
        $temporary_directory = $directory;
2475
        break;
2476
      }
2477
    }
2478

    
2479
    if (empty($temporary_directory)) {
2480
      // If no directory has been found default to 'files/tmp'.
2481
      $temporary_directory = variable_get('file_public_path', conf_path() . '/files') . '/tmp';
2482

    
2483
      // Windows accepts paths with either slash (/) or backslash (\), but will
2484
      // not accept a path which contains both a slash and a backslash. Since
2485
      // the 'file_public_path' variable may have either format, we sanitize
2486
      // everything to use slash which is supported on all platforms.
2487
      $temporary_directory = str_replace('\\', '/', $temporary_directory);
2488
    }
2489
    // Save the path of the discovered directory.
2490
    variable_set('file_temporary_path', $temporary_directory);
2491
  }
2492

    
2493
  return $temporary_directory;
2494
}
2495

    
2496
/**
2497
 * Examines a file object and returns appropriate content headers for download.
2498
 *
2499
 * @param $file
2500
 *   A file object.
2501
 *
2502
 * @return
2503
 *   An associative array of headers, as expected by file_transfer().
2504
 */
2505
function file_get_content_headers($file) {
2506
  $name = mime_header_encode($file->filename);
2507
  $type = mime_header_encode($file->filemime);
2508

    
2509
  return array(
2510
    'Content-Type' => $type,
2511
    'Content-Length' => $file->filesize,
2512
    'Cache-Control' => 'private',
2513
  );
2514
}
2515

    
2516
/**
2517
 * @} End of "defgroup file".
2518
 */